On May 28, 2008, shortly before 6 p.m., two westbound MBTA trains collided on the Green Line D branch between Woodland and Waban stations, behind 56 Dorset Road in Newton, Massachusetts.

[2] An investigation by the National Transportation Safety Board (NTSB) originally found the cause of the accident to be due to the operator texting while driving,[dubious – discuss] but the NTSB later found that the operator of the rear train, Terrese Edmonds, had not been using her cell phone at the time of the crash, but rather went into an episode of micro-sleep, causing her to lose awareness of her surroundings and miss potential hazards up ahead.

[3] This crash, along with another similar accident a year later, led the NTSB to set higher standards and regulations regarding the use of cell phones while operating a train.

[1]: 4  The operator of Train 3667, Terrese Edmonds, suffered blunt force trauma during the collision and was killed; 8 passengers were injured.

[6] The NTSB determined that an episode of micro-sleep caused by sleep apnea was likely the reason for the operator losing awareness of her environment.

The qualifications for the job included a high school diploma, a valid driver's license, a background check, and seven weeks of training.